Coil components and electronic devices
By providing grooves and metal films with a larger cross-sectional area, the terminal portion is formed by solving the problem of poor solder diffusion during welding and improving the bonding strength and reliability of the coil.
Patent Information
- Application Number
- CN201910900279.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Priority Date
- 2018-09-28
- Filing Date
- 2019-09-23
- Publication Date
- 2024-12-31
- Estimated Expiration
- 2039-09-23
AI Technical Summary
It is difficult for existing coil components to stably connect the wires and metal films during welding, which makes it difficult for solder to diffuse, affecting the bonding quality of the electrode and the reliability of the coil.
A coil component is designed, which includes a magnetic core, a conductor surround wound with an insulating coating and a conductor led out of the flange. By providing a metal film and solder in the groove of the flange, a larger cross-sectional area is formed. The terminal portion ensures that the solder can be effectively wet and diffused, and enhances bonding strength.
It effectively improves welding quality, reduces the adhesion of flux residue to the surround, extends the service life of the coil and improves reliability.
Smart Images
Figure CN110970200B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a coil component and an electronic device. Background Art
[0002] A coil component is known in which a conductor wound on a reel of a drum core is led out into a groove provided on the outer surface of a flange portion, and the end of the conductor led out into the groove is joined to a metal film provided in the groove by soldering to form an electrode. For example, a method is known in which, in order to stably connect the conductor and the metal film by soldering, the flange portion is immersed in a solder bath, the drum core is rotated at a predetermined speed so that the extending direction of the groove becomes a tangential direction, and the drum core is lifted from the solder bath (for example, Patent Document 1).
[0003] Prior art literature
[0004] Patent Literature
[0005] Patent Document 1: Japanese Patent Application Publication No. 2011-165706 Summary of the invention
[0006] Methods for solving problems
[0007] The present invention is a coil component, which includes: a core portion, which includes a winding shaft and a flange portion, wherein the flange portion is arranged in a plate shape at the axial end of the above-mentioned winding shaft, and has an outer surface on the opposite side of the above-mentioned winding shaft, a groove portion arranged on the above-mentioned outer surface, a first side surface intersecting with the long axis of the above-mentioned groove portion, and a first recessed portion arranged on the above-mentioned first side surface; a coil portion, which includes a surrounding portion wound with a conductor having an insulating coating and a lead-out portion from the above-mentioned surrounding portion along the above-mentioned first side surface of the above-mentioned flange portion to lead out the above-mentioned conductor and into the above-mentioned groove portion of the above-mentioned flange portion; and a terminal portion, which is arranged in the above-mentioned groove portion of the above-mentioned flange portion without being adjacent to the above-mentioned first side surface, and includes an end portion of the above-mentioned insulating coating of the above-mentioned lead-out portion and a solder portion, wherein the cross-sectional area of the surface parallel to the above-mentioned first side surface of the space portion formed on the above-mentioned first side surface as the above-mentioned first recess is larger than the cross-sectional area of the surface parallel to the above-mentioned first side surface of the above-mentioned groove portion connected to the above-mentioned terminal portion.
[0008] The present invention is an electronic device including the coil component described above and a circuit substrate on which the coil component is mounted.
[0009] Description of Reference Numerals
[0010] 10 Drum core
[0011] 12 Scrolls
[0012] 14a, 14b flange portion
[0013] 20, 22, 24, 26 Side
[0014] 28 Inner surface
[0015] 30 External surface
[0016] 32a, 32b groove portion
[0017] 34a, 34b recess
[0018] 35 Bottom
[0019] 36a, 36b recess
[0020] 37 bevel
[0021] 38, 38a recess
[0022] 40 Coil
[0023] 42 Surrounding part
[0024] 44a, 44b Lead-out portion
[0025] 46 Wire
[0026] 48 Insulation coating
[0027] 50 Metal Wire
[0028] 60a, 60b Metal film
[0029] 70a, 70b Terminal part
[0030] 72 Solder
[0031] 74 resin film
[0032] 80 Circuit board
[0033] 82 Electrode
[0034] 90 Drum Core
[0035] 92 Scroll
[0036] 94a, 94b flange portion
[0037] 100, 1000 Coil parts
[0038] 800 Electronic equipment BRIEF DESCRIPTION OF THE DRAWINGS
[0039] Figure 1 (a) is a three-dimensional view of the coil component of Example 1, Figure 1 (b) is perspective Figure 1 (a) is a three-dimensional view of the resin film and solder.
[0040] Figure 2 (a) to Figure 2(c) is a diagram showing the drum core of Example 1.
[0041] Figure 3 (a) to Figure 3 (c) is a perspective view showing the method for manufacturing the coil component of Example 1 (Part 1).
[0042] Figure 4 (a) and Figure 4 (b) is a perspective view showing the method for manufacturing the coil component of Example 1 (part 2).
[0043] Figure 5 (a) is a perspective view of a coil component of a comparative example, Figure 5 (b) is perspective Figure 5 (a) A perspective view of solder and resin film.
[0044] Figure 6 (a) to Figure 6 (c) is a diagram showing a drum core of a comparative example.
[0045] Figure 7 (a) and Figure 7 (b) is a diagram showing the drum core of Example 2.
[0046] Figure 8 (a) and Figure 8 (b) is a diagram showing the drum core of Example 3.
[0047] Fig. 9 (a) and Fig. 9 (b) is a diagram showing the drum core of Example 4.
[0048] Fig.10 This is a stereoscopic view of the drum core of Example 5.
[0049] Fig.11 This is a stereoscopic view of the drum core of Example 6.
[0050] Fig.12 This is a stereoscopic view of the drum core of Example 7.
[0051] Fig.13 This is a cross-sectional view of the electronic device of Example 8. DETAILED DESCRIPTION
[0052] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[0053] (Example 1)
[0054] Figure 1 (a) is a three-dimensional view of the coil component of Example 1, Figure 1 (b) is perspective Figure 1 (a) is a three-dimensional image of the resin film and solder. Figure 1 (a) and Figure 1 As shown in (b), the coil component 100 of the first embodiment includes the drum core 10, the coil portion 40, and the terminal portions 70a and 70b.
[0055] Figure 2 (a) to Figure 2 (c) is a diagram showing the drum core of Example 1. Figure 2 (a) is from Figure 1 (a) is a side view of the drum core 10 when viewed from the direction A, Figure 2 (b) is from Figure 1 (a) is a side view of the drum core 10 when viewed from the direction B, Figure 2 (c) is from Figure 1 (a) is a top view of the drum core 10 when viewed from the C direction. Figure 2 (a) to Figure 2 As shown in (c), the drum core 10 includes a reel 12, and plate-like flange portions 14a and 14b provided at both ends of the axial direction of the reel 12. The thickness dimension T1 of the flange portion 14a is 0.15 mm to 0.55 mm. The thickness dimension T2 of the flange portion 14b is 0.2 mm to 0.7 mm. The thickness dimension T2 of the flange portion 14b is greater than the thickness dimension T1 of the flange portion 14a. The reel 12 is, for example, a columnar shape whose bottom surface contour is formed by a straight line and two arcs. The flange portion 14a is a rectangular parallelepiped.
[0056] The flange portion 14b has four side surfaces, namely, a side surface 20, a side surface 22 located on the opposite side to the side surface 20 with the reel 12 interposed therebetween, a side surface 24 adjacent to the side surface 20 and the side surface 22, and a side surface 26 located on the opposite side to the side surface 24 with the reel 12 interposed therebetween. In addition, the flange portion 14b has an inner surface 28 connected to the reel 12 and an outer surface 30 on the opposite side to the inner surface 28 connected to the reel 12. Grooves 32a and 32b are provided on the outer surface 30 of the flange portion 14b. The grooves 32a and 32b extend in a direction intersecting the side surfaces 20 and 22. In other words, the side surfaces 20 and 22 are side surfaces intersecting with the major axes of the grooves 32a and 32b. As an example, the grooves 32a and 32b are tapered in a manner that narrows in width as they approach the bottom surface 35. That is, the grooves 32a and 32b have a bottom surface 35 and two inclined surfaces 37 adjacent to the bottom surface 35 and whose widths become narrower as they go toward the bottom surface 35. The shape of the grooves 32a and 32b may also be composed of the bottom surface 35 and the side surfaces perpendicularly adjacent to the bottom surface 35. In addition, the bottom surface 35 and / or the side surfaces may be curved surfaces, and any shape may be possible as long as they are groove-shaped.
[0057] As an example, the depth dimension of the grooves 32a and 32b is 0.1 mm to 0.3 mm, which is less than 1 / 2 of the thickness dimension of the flange 14b. The deeper the grooves 32a and 32b, the thinner the flange 14b becomes and the lower the strength is. Therefore, the depth dimension of the grooves 32a and 32b is preferably less than 1 / 3 of the thickness dimension of the flange 14b, and more preferably less than 1 / 4. The width dimension of the opening side and the bottom side of the grooves 32a and 32b is approximately constant from one end to the other end in the longitudinal direction of the grooves 32a and 32b, and is 0.2 mm to 2.5 mm on the opening side and 0.1 mm to 1.0 mm on the bottom side.
[0058] Recesses 34a and 34b are provided on the side surfaces 20 and 22 of the flange portion 14b and at the adjacent portions of the side surfaces 20 and 22 and the outer surface 30. The recesses 34a and 34b extend from one side surface to the other side surface of a pair of side surfaces 24 and 26 of the flange portion 14b. That is, the recesses 34a and 34b are provided in contact with the side surfaces 24 and 26. The axial depth dimension of the reel 12 of the recesses 34a and 34b is, for example, substantially the same as the axial depth dimension of the reel 12 of the grooves 32a and 32b. In addition, the so-called substantially the same includes differences in the degree of manufacturing errors.
[0059] The drum core 10 is formed by including a magnetic material. For example, the drum core 10 is formed by including a ferrite material of the Ni-Zn or Mn-Zn type, a soft magnetic alloy material such as a Fe-Si-Cr type, a Fe-Si-Al type or a Fe-Si-Cr-Al type, a magnetic metal material such as Fe or Ni, an amorphous magnetic metal material or a nanocrystalline magnetic metal material. In the case of being formed by a ferrite material, the drum core 10 can also be formed by sintering the ferrite material. In the case of being formed by metal magnetic particles, the drum core 10 can be formed by fixing the metal magnetic particles with a resin, or by bonding the insulating films formed on the surfaces of the metal magnetic particles to each other.
[0060] like Figure 1 (a) and Figure 1 As shown in (b), the coil portion 40 includes a surrounding portion 42 around which a conductive wire 46 having an insulating coating 48 is wound, and lead portions 44a and 44b from which the conductive wire 46 is led out of the surrounding portion 42. The conductive wire 46 has a diameter of 0.05 mm or more and a conductor cross-sectional area of 0.00196 mm 2 Above and 0.0236mm 2 Next, the surface of the metal wire 50 as a conductor is covered with the insulating film 48. The metal wire 50 covered with the insulating film 48 is formed of, for example, copper, silver, palladium, or a silver-palladium alloy. The insulating film 48 is formed of, for example, polyesterimide or polyamide.
[0061] The lead portions 44a and 44b are bent along the side surface 20 of the flange portion 14b to be led out, and are further bent along the outer surface 30 of the flange portion 14b to be led out into the groove portions 32a and 32b provided on the outer surface 30 of the flange portion 14b. The end portions of the lead portions 44a and 44b inserted into the groove portions 32a and 32b are stripped of the insulating coating 48 to expose the metal wire 50. The depth dimension of the groove portions 32a and 32b is preferably greater than the diameter of the wire 46 so that the wire 46 is only in the groove portions 32a and 32b. The width dimension of the bottom surface side of the groove portions 32a and 32b is preferably greater than 1.0 times the diameter of the wire 46, more preferably greater than 1.2 times, and further preferably greater than 1.4 times.
[0062] Metal films 60a and 60b are provided in the grooves 32a and 32b. The metal films 60a and 60b are provided to cover the inclined surfaces 37 and the bottom surfaces 35 of the grooves 32a and 32b. The metal films 60a and 60b are formed of a laminated metal layer in which a nickel layer and a tin layer are provided on a base layer such as copper, silver, palladium or a silver-palladium alloy.
[0063] The ends of the exposed metal wires 50 of the lead-out portions 44a and 44b are joined to the metal films 60a and 60b provided in the grooves 32a and 32b through the solder 72. Thus, the terminal portions 70a and 70b are formed. That is, the terminal portions 70a and 70b are formed by the ends of the exposed metal wires 50 of the lead-out portions 44a and 44b, the solder 72, and the metal films 60a and 60b. The solder 72 is buried in the grooves 32a and 32b and is not exposed outside the grooves 32a and 32b. This is because the solder 72 infiltrates and diffuses on the metal films 60a and 60b with good solder wettability, but it is difficult to infiltrate and diffuse on the drum core 10 with poor solder wettability. The solder 72 is formed to be flush with the outer surface 30 of the flange portion 14b, or is formed to be slightly raised compared to the outer surface 30.
[0064] The recessed portions 34a and 34b of the side surfaces 20 and 22 of the flange portion 14b are provided in contact with the groove portions 32a and 32b on the outer surface 30 side of the side surfaces 20 and 22. Thus, the cross-sectional area of the groove portions 32a and 32b in contact with the terminal portions 70a and 70b (equivalent to Figure 2 (a) The narrow shaded area) of the space with a large cross-sectional area (equivalent to Figure 2(a) is formed between the side surfaces 20 and 22 of the terminal portions 70a and 70b and the flange portion 14b. That is, the cross-sectional area of the surface parallel to the side surface 20 of the space portion formed on the side surface 20 as the recess 34a is larger than the cross-sectional area of the surface parallel to the side surface 20 of the groove portions 32a and 32b connected to the terminal portions 70a and 70b. Similarly, the cross-sectional area of the surface parallel to the side surface 22 of the space portion formed on the side surface 22 as the recess 34b is larger than the cross-sectional area of the surface parallel to the side surface 22 of the groove portions 32a and 32b connected to the terminal portions 70a and 70b.
[0065] A resin film 74 is provided between the flange 14a and the flange 14b to cover the surrounding portion 42 of the coil portion 40. The resin film 74 is only between the flange 14a and the flange 14b and does not protrude outside the flanges 14a and 14b, which is preferred from the perspective of miniaturization of the component. The resin film 74 is formed of a resin (e.g., an insulating resin such as epoxy resin) containing ferrite particles or metal magnetic particles. In addition, the resin film 74 may not be provided.
[0066] The coil component 100 has a height H of 0.8 mm to 4.5 mm, a length L of 1.6 mm to 7.0 mm, and a width W of 0.8 mm to 7.0 mm. In addition, the height H is a value including the protruding portion of the solder 72, and the height after omitting the solder 72 is 0.75 mm to 4.3 mm. The thickness of the metal films 60a and 60b is 0.05 mm to 0.2 mm.
[0067] Figure 3 (a) to Figure 4 (b) is a perspective view showing the method for manufacturing the coil component of Example 1. Figure 3 As shown in (a), for example, a composite magnetic material mixed with magnetic particles and resin is filled into a metal mold and compression-molded to form a drum core 10 having a reel 12 and flanges 14a and 14b provided at both ends of the reel 12. Grooves 32a and 32b and recesses 34a and 34b are formed in the flange 14b. In addition, the grooves 32a and 32b and the recesses 34a and 34b can also be formed by grinding after molding.
[0068] like Figure 3 As shown in (b), metal films 60a and 60b are formed in the grooves 32a and 32b of the flange 14b by, for example, forming a base layer by sputtering and then forming a plated layer on the base layer by electroplating. Alternatively, the base layer may be formed by applying a conductive paste.
[0069] like Figure 3As shown in (c), a wire 46 covered with an insulating coating 48 is wound around the reel 12 of the drum core 10 and bent at both ends of the wire 46 to form a coil portion 40 including a surrounding portion 42 wound around the reel 12 and lead portions 44a and 44b led from the surrounding portion 42 to the grooves 32a and 32b of the flange portion 14b. The coil portion 40 can also be prepared separately and bent after being combined with the drum core 10. The ends of the lead portions 44a and 44b located in the grooves 32a and 32b are coated with flux 52.
[0070] like Figure 4 As shown in (a), the ends of the lead portions 44a and 44b coated with the flux 52 are heated together with the solder, and the insulating coating 48 is peeled off by the action of the flux 52, and the exposed portion of the metal wire 50 is joined to the metal films 60a and 60b by the solder 72. Thus, the terminal portions 70a and 70b are formed. The solder 72 infiltrates and diffuses in the metal films 60a and 60b and fills the grooves 32a and 32b. The solder 72 is not easy to infiltrate and diffuse in the drum core 10 with poor solder wettability, so it is difficult to diffuse outside the grooves 32a and 32b. The lead portions 44a and 44b can be joined to the metal films 60a and 60b by heating the ends coated with flux 52 using solder 72 pre-formed on the metal films 60a and 60b, or by leading the ends coated with flux 52 into the grooves 32a and 32b and then immersing them together with the flange portion 14b in a solder bath.
[0071] like Figure 4 As shown in (b), a composite magnetic material in which magnetic particles and resin are mixed is applied between the flange portion 14a and the flange portion 14b and outside the surrounding portion 42, and then the resin is cured to form a resin film 74.
[0072] Figure 5 (a) is a perspective view of a coil component of a comparative example, Figure 5 (b) is perspective Figure 5 (a) is a three-dimensional view of the resin film and solder. Figure 6 (a) to Figure 6 (c) is a diagram showing a drum core of a comparative example. Figure 5 (a) and Figure 5 (b) and Figure 6 (a) to Figure 6(c) shows, in the coil component 1000 of the comparative example, a drum core 90 having a reel 92 and flanges 94a and 94b is used instead of the drum core 10. No recesses 34a and 34b are formed in the flange 94b. The grooves 32a and 32b provided on the outer surface 30 of the flange 94b extend from the side 20 of the flange 94b to the opposite side 22. Other structures are the same as in Example 1, so description is omitted.
[0073] As described in the manufacturing method of Example 1, the ends of the lead portions 44a and 44b are solder-joined to the metal films 60a and 60b. Therefore, when the flux 52 is applied to the ends of the lead portions 44a and 44b for solder-joining, the insulating film 48 is peeled off. When a wire 46 with a large diameter is used to cope with a large current, the insulating film 48 becomes thicker, and the amount of flux 52 used increases. Therefore, liquid flux 52 that has not been vaporized by the heat of solder-joining and / or liquid flux 52 that has been vaporized and cooled to be liquefied is easily attached to the wire 46 and / or the grooves 32a and 32b. The residue of the flux 52 may move to the surrounding portion 42 via the lead portions 44a and 44b over time due to, for example, humidity in the air. As a result, the insulating film 48 of the surrounding portion 42 may become thinner or removed, and the characteristics may deteriorate.
[0074] In the comparative example, the grooves 32a and 32b are directly connected to the side surfaces 20 and 22 of the flange 94b without passing through the recess. Therefore, the distance between the terminal portions 70a and 70b and the surrounding portion 42 of the coil portion 40 through the lead portions 44a and 44b is shortened. As a result, the residue of the flux 52 attached to the wire 46 and / or the grooves 32a and 32b is likely to move to the surrounding portion 42 through the lead portions 44a and 44b over time, thereby easily causing degradation of the characteristics.
[0075] On the other hand, according to Example 1, Figure 1 (a) Figure 1 (b) and Figure 2As shown in (a), the terminal parts 70a and 70b are not arranged next to the side 20 of the flange part 14b. On the side 20 of the flange part 14b, a recessed part 34a is provided on the outer surface 30 side in contact with the groove parts 32a and 32b to form a space with a cross-sectional area larger than the cross-sectional area of the surface parallel to the side 20 and the cross-sectional area of the groove parts 32a and 32b connected to the terminal parts 70a and 70b. That is, the cross-sectional area of the surface parallel to the side 20 of the space part formed by the recessed part 34a on the side 20 is larger than the cross-sectional area of the surface parallel to the side 20 of the groove parts 32a and 32b connected to the terminal parts 70a and 70b. As a result, the distance between the terminal parts 70a and 70b and the surrounding part 42 of the coil part 40 through the lead-out parts 44a and 44b can be lengthened. In addition, even if the residue of the flux 52 passes through the lead portions 44a and 44b, the residue of the flux 52 can be left in the recessed portion 34a. Furthermore, since the groove portions 32a and 32b are shortened, the area of the lead portions 44a and 44b where the insulating coating 48 is peeled off becomes smaller, and the amount of flux 52 used is reduced, the generation of the residue of the flux 52 itself can be reduced. Therefore, the residue of the flux 52 attached to the wire 46 and / or the groove portions 32a and 32b can be suppressed from being attached to the surrounding portion 42 through the lead portions 44a and 44b. As a result, the degradation of characteristics over time can be suppressed, and the reduction in reliability can be suppressed.
[0076] like Figure 1 (a) and Figure 1 As shown in (b), it is preferred that the width dimension of the cross section of the recessed portion 34a parallel to the side surface 20 of the flange portion 14b and perpendicular to the axial direction of the reel 12 is greater than the width dimension of the cross section parallel to the side surface 20 of the groove portions 32a and 32b and perpendicular to the axial direction of the reel 12. Thus, a large amount of the residue of the flux 52 can be left in the recessed portion 34a, and the residue of the flux 52 can be effectively prevented from adhering to the surrounding portion 42.
[0077] like Figure 1 (a) Figure 1 (b) and Figure 2 As shown in (c), it is preferable that the recessed portion 34a is provided in contact with a pair of side surfaces 24 and 26 of the flange portion 14b. As a result, the volume of the recessed portion 34a becomes larger, so that more residues of the flux 52 passing through the lead portions 44a and 44b can be retained in the recessed portion 34a. As a result, the residues of the flux 52 can be further suppressed from adhering to the surrounding portion 42.
[0078] like Figure 1 (a) and Figure 1As shown in (b), it is preferred that the flange portion 14b is provided with a recessed portion 34a not only on the side 20 but also on the side 22. That is, on the side 22 of the flange portion 14b, a recessed portion 34b is provided on the outer surface 30 side in contact with the grooves 32a and 32b so as to form a space having a larger cross-sectional area than the cross-sectional area of the surface parallel to the side 22 and the cross-sectional area of the grooves 32a and 32b contacting the terminal portions 70a and 70b. That is, the cross-sectional area of the surface parallel to the side 22 of the space portion formed as the recessed portion 34b on the side 22 is larger than the cross-sectional area of the surface parallel to the side 22 of the grooves 32a and 32b contacting the terminal portions 70a and 70b. As a result, the direction of the lead-out portion from the surrounding portion to the grooves 32a and 32b can be increased to two directions. Therefore, in the lead-out process, the procedure for correcting the direction of the drum core 10 can be simplified and productivity can be improved. Furthermore, for example, the present invention can also cope with a coil component such as a common mode choke coil in which two coils are wound around the drum core 10 .
[0079] like Figure 1 As shown in (b), it is preferred that the length direction of the grooves 32a and 32b is substantially parallel to the short side of the outer surface 30 of the flange 14b, and the width direction of the grooves 32a and 32b is substantially parallel to the long side of the outer surface 30 of the flange 14b. That is, the side surface 20 of the flange 14b is substantially parallel to the long side of the outer surface 30. Thus, the width of the grooves 32a and 32b can be increased, thereby increasing the area of the metal films 60a and 60b. Thus, the metal films 60a and 60b can be prevented from peeling off from the drum core 10. In addition, substantially parallel includes an inclination of the degree of manufacturing error.
[0080] like Figure 1 As shown in (b), it is preferable that the width dimension of the grooves 32a and 32b in the direction parallel to the side surface 20 of the flange 14b and the opening of the grooves 32a and 32b is substantially constant from one end to the other end in the longitudinal direction perpendicular to the side surface 20. In this way, it is possible to ensure a sufficient width required for inserting the ends of the lead-out portions 44a and 44b, to reduce the area where the thickness of the flange 14b is thinned, and to suppress the reduction in the strength of the flange 14b. In addition, substantially constant includes differences in the degree of manufacturing error.
[0081] The width of the recessed portions 34a and 34b in the direction perpendicular to the side surfaces 20 and 22 of the flange portion 14b is preferably wider in order to leave more residue of the flux 52. However, if it is too wide, the length of the grooves 32a and 32b will be shortened, and the bonding strength between the lead portions 44a and 44b and the metal films 60a and 60b will be reduced. Therefore, the width of the recessed portions 34a and 34b in the direction perpendicular to the side surface 20 of the flange portion 14b is preferably 0.1 times or more and 0.4 times or less, and more preferably 0.2 times or more and 0.3 times or less relative to the width of the flange portion 14b in the direction perpendicular to the side surface 20 of the flange portion 14b.
[0082] (Example 2)
[0083] Figure 7 (a) and Figure 7 (b) is a diagram showing the drum core of Example 2. Figure 7 (a) and Figure 7 As shown in (b), in the coil component of Example 2, the axial depth dimension of the winding shaft 12 of the recessed portions 34a and 34b provided in the flange portion 14b is deeper than the axial depth dimension of the winding shaft 12 of the groove portions 32a and 32b provided in the flange portion 14b. The other structures of the coil component of Example 2 are the same as those of the coil component of Example 1, so illustration and description are omitted.
[0084] According to the second embodiment, the depth dimension of the concave portion 34a in the axial direction of the winding shaft 12 is greater than the depth dimension of the groove portions 32a and 32b in the axial direction of the winding shaft 12. As a result, the volume of the concave portion 34a is increased, so that a large amount of the residue of the flux 52 passing through the lead portions 44a and 44b can be retained in the concave portion 34a. As a result, the residue of the flux 52 can be further suppressed from being attached to the surrounding portion 42.
[0085] In order to retain more residues of the flux 52, the axial depth dimension of the reel 12 of the recesses 34a and 34b is preferably 1.2 times or more, more preferably 1.5 times or more, and further preferably 2.0 times or more of the axial depth dimension of the reel 12 of the grooves 32a and 32b. On the other hand, if the recesses 34a and 34b are too deep, the strength of the portion of the flange 14b where the recesses 34a and 34b are provided will decrease. Therefore, the axial depth dimension of the reel 12 of the recesses 34a and 34b is preferably 0.6 times or less, more preferably 0.5 times or less, and further preferably 0.4 times or less of the thickness of the flange 14b.
[0086] (Example 3)
[0087] Figure 8 (a) and Figure 8 (b) is a diagram showing the drum core of Example 3. Figure 8 (a) and Figure 8As shown in (b), in the coil component of Example 3, the side surfaces of the recesses 34a and 34b provided in the flange portion 14b are tapered. That is, the recesses 34a and 34b are shaped as tapered surfaces when viewed from the side surfaces 20 and 22 of the flange portion 14b. The depth dimension of the deepest part of the axial direction of the reel 12 of the recesses 34a and 34b is, for example, deeper than the axial depth dimension of the reel 12 of the grooves 32a and 32b, but may also be substantially the same as the axial depth dimension of the reel 12 of the grooves 32a and 32b. The other structures of the coil component of Example 3 are the same as those of the coil component of Example 1, and therefore illustration and description are omitted.
[0088] According to the third embodiment, the recesses 34a and 34b have a tapered shape when viewed from the side surfaces 20 and 22 of the flange 14b. As a result, the thickness of the flange 14b of the recesses 34a and 34b can be ensured and the volume of the recesses 34a and 34b can be increased. As a result, the strength of the flange 14b can be suppressed from decreasing and the residue of the flux 52 can be left in the recesses 34a and 34b, and the residue of the flux 52 can be suppressed from adhering to the surrounding portion 42.
[0089] Furthermore, since the side surface of the recessed portion 34 a is tapered, bending work for leading the lead wire 46 to the outer surface 30 of the flange portion 14 b becomes easy.
[0090] (Example 4)
[0091] Fig. 9 (a) and Fig. 9 (b) is a diagram showing the drum core of Example 4. Fig. 9 (a) and Fig. 9 As shown in (b), in the coil component of Example 4, not only are recesses 34a and 34b provided at the adjacent portions of the side surfaces 20 and 22 of the flange portion 14b and the outer surface 30, but recesses 36a and 36b are also provided at the adjacent portions of the side surfaces 20 and 22 and the inner surface 28. As an example, the axial depth dimension of the recesses 36a and 36b in the winding shaft 12 may be substantially the same as or different from the axial depth dimension of the recesses 34a and 34b in the winding shaft 12. As an example, the width of the recesses 36a and 36b in the direction perpendicular to the side surfaces 20 and 22 of the flange portion 14b may be substantially the same as or different from the width of the recesses 34a and 34b in the direction perpendicular to the side surfaces 20 and 22 of the flange portion 14b. The recesses 36a and 36b, like the recesses 34a and 34b, may also extend from one side of a pair of side surfaces 24 and 26 of the flange portion 14b to the other side surface, and lead-out portions 44a and 44b may be provided at least at the lead-out portions. The other structures of the coil component of the fourth embodiment are the same as those of the coil component of the first embodiment, and therefore illustration and description thereof are omitted.
[0092] According to the fourth embodiment, the side surface 20 of the flange portion 14b has a recessed portion 36a at a portion where the inner surface 28 and the side surface 20 are adjacent and where the lead-out portions 44a and 44b are led out. Thus, the residue of the flux 52 passing through the lead-out portions 44a and 44b can be retained in the recessed portion 36a before reaching the surrounding portion 42. Thus, the residue of the flux 52 can be further suppressed from being attached to the surrounding portion 42.
[0093] The recesses 34a and 34b and the recesses 36a and 36b both have the function of retaining the residue of the soldering flux 52, but the recesses 36a and 36b only play an auxiliary role, so the depth dimension of the recesses 36a and 36b in the axial direction of the reel 12 can be made shallower than the depth dimension of the recesses 34a and 34b in the axial direction of the reel 12. As a result, the flange portion 14b in the portion where the recesses 34a and 34b and the recesses 36a and 36b are provided can be suppressed from becoming thinner, and the strength of the flange portion 14b can be suppressed from being reduced. In addition, from the viewpoint of suppressing the strength reduction of the flange portion 14b, the width dimension of the recesses 36a and 36b in the direction perpendicular to the side surfaces 20 and 22 of the flange portion 14b can also be smaller than the width dimension of the recesses 34a and 34b in the direction perpendicular to the side surfaces 20 and 22 of the flange portion 14b.
[0094] [Example 5]
[0095] Fig.10 is a stereoscopic view of the drum core of Example 5. Fig.10 Also shown in FIG. 1 are terminal portions 70a and 70b in the areas defined by the metal films 60a and 60b. Fig.10 As shown, the recessed portions 34a and 34b may not extend from one side to the other side of the pair of side surfaces 24 and 26 of the flange portion 14b. In this case, for the same reason as in the first embodiment, the residue of the flux 52 can be suppressed from adhering to the surrounding portion 42.
[0096] [Example 6]
[0097] Fig.11 is a stereoscopic view of the drum core of Example 6. Fig.11 Also shown in FIG. 1 are terminal portions 70a and 70b in the areas defined by the metal films 60a and 60b. Fig.11As shown, in the coil component of Example 6, a recess 38 is provided on the outer surface 30 side of the side 20 and 22 of the flange portion 14b. The cross-sectional shape of the surface of the recess 38 provided on the side 20, which is farthest from the side 20 and is parallel to the side 20 and forms the boundary with the grooves 32a and 32b provided with the terminal portions 70a and 70b, is equal to the cross-sectional shape of the surface of the grooves 32a and 32b provided with the terminal portions 70a and 70b, which is parallel to the side 20 and forms the boundary of the recess 38. The cross-sectional shape of each surface when the recess 38 provided on the side 20 is decomposed into each surface parallel to the side 20 becomes a cross-sectional shape in which the area becomes larger as the distance between the side 20 and each surface becomes closer, and the surface formed by connecting each surface becomes a tapered cross-sectional shape. In addition, the surface formed by connecting each surface parallel to the side 20 of the recess 38 provided on the side 20 is a tapered plane that is continuous with the bottom surface 35 and the inclined surface 37 of the grooves 32a and 32b, respectively. The recessed portion 38 provided on the side surface 22 has the same shape as the recessed portion 38 provided on the side surface 20 , but description thereof will be omitted here.
[0098] The recess 38 is a shape having a surface that is concave in a tapered manner from the bottom surface 35 of the grooves 32a and 32b where the terminal parts 70a and 70b meet toward the side surfaces 20 and 22. In addition, the recess 38 is a shape having a surface that is tapered and inclined in a manner that widens from the inclined surface 37 of the grooves 32a and 32b where the terminal parts 70a and 70b meet toward the side surfaces 20 and 22. The other structures of the coil component of the sixth embodiment are the same as those of the first embodiment, so illustration and description are omitted.
[0099] According to the sixth embodiment, the cross-sectional shape of the surface of the recess 38 provided on the side 20 of the flange portion 14b, which is farthest from the side 20 and is parallel to the side 20 and forms the boundary with the grooves 32a and 32b, is equal to the cross-sectional shape of the surface of the grooves 32a and 32b, which is parallel to the side 20 and forms the boundary with the recess 38. Moreover, the cross-sectional shape of each surface of the recess 38 parallel to the side 20 is a cross-sectional shape in which the area increases as the distance between the side 20 and each surface becomes closer, and the cross-sectional shape formed by connecting each surface becomes a tapered surface. In this case, as in the first embodiment, the distance between the terminal portions 70a and 70b and the surrounding portion 42 of the coil portion 40 through the lead portions 44a and 44b can be lengthened. In addition, in the case where the residue of the flux 52 passes through the lead portions 44a and 44b, the residue of the flux 52 can also be left more in the recess 38. Furthermore, the area of the lead portions 44a and 44b where the insulating coating 48 is stripped is reduced, and the amount of flux 52 used is reduced, so that the generation of the residue of the flux 52 itself can be reduced. Therefore, the residue of the flux 52 attached to the wire 46 and / or the groove portions 32a and 32b can be suppressed from being attached to the surrounding portion 42 through the lead portions 44a and 44b.
[0100] [Example 7]
[0101] Fig.12 is a stereoscopic view of the drum core of Example 7. Fig.12 Also shown in FIG. 1 are terminal portions 70a and 70b in the areas defined by the metal films 60a and 60b. Fig.12 As shown, in the coil component of Example 7, the recess 38a is in the shape of a surface that is stepped down from the bottom surface 35 of the grooves 32a and 32b where the terminal portions 70a and 70b meet toward the side surfaces 20 and 22 of the flange portion 14b. The other structures are the same as those of Example 6, so the description is omitted.
[0102] As shown in Example 6, the concave portion 38 may have a shape in which the surface formed by connecting the surfaces parallel to the side surface 20 of the flange portion 14b is a tapered plane continuous with the bottom surface 35 and the inclined surface 37 of the groove portions 32a and 32b, respectively. As shown in Example 7, the concave portion 38a may be formed so that the bottom surface 35 of the groove portions 32a and 32b is recessed in a stepped shape.
[0103] In addition, in Examples 1 to 5, as in Examples 6 and 7, the portion of the recess 34a located between the bottom surface 35 of the grooves 32a and 32b and the side surface 20 of the flange portion 14b may also be a shape that is recessed compared to the bottom surface 35 of the grooves 32a and 32b.
[0104] [Example 8]
[0105] Fig.13 is a cross-sectional view of an electronic device of Example 8. Fig.13 As shown, the electronic device 800 of the eighth embodiment includes a circuit board 80 and the coil component 100 of the first embodiment mounted on the circuit board 80. The coil component 100 is mounted on the circuit board 80 by bonding to an electrode 82 of the circuit board 80 with solder 72.
[0106] According to the electronic device 800 of the eighth embodiment, the coil component 100 of the first embodiment is mounted on the circuit substrate 80. Thus, the electronic device 800 having the coil component 100 with reduced reliability can be obtained. In addition, in the eighth embodiment, the case where the coil component 100 of the first embodiment is mounted on the circuit substrate 80 is illustrated, but the coil components of the second to seventh embodiments may also be mounted.
[0107] As mentioned above, although the embodiment of the present invention has been described in detail, the present invention is not limited to the specific embodiment, and various modifications and changes can be made within the scope of the gist of the present invention described in the scope of the invention.
Claims
1. A coil component, characterized in that: include: A magnetic core portion, comprising a winding shaft and a flange portion, wherein the flange portion is formed in a plate shape at an axial end portion of the winding shaft and has an outer surface on a side opposite to the winding shaft, a groove portion formed on the outer surface, a first side surface intersecting with a long axis of the groove portion, and a first recessed portion formed on the first side surface; a coil portion including a surrounding portion around which a conductor having an insulating coating is wound and a lead-out portion from which the conductor is led out along the first side surface of the flange portion and into the groove portion of the flange portion; and a terminal portion formed in the groove portion of the flange portion away from the first side surface, and including an end portion of the lead portion from which the insulating coating is peeled off and a solder portion, The first side surface has an upper portion located on the outer surface side and a lower portion located on the reel side, and the first recess is provided only on the upper portion. The first recessed portion is connected to the groove portion in the direction of the long axis, and when viewed along the axial direction of the reel, the first recessed portion is interposed between the groove portion and the first side surface. A cross-sectional area of a surface parallel to the first side surface of a space portion formed as the first recess on the first side surface is larger than a cross-sectional area of a surface parallel to the first side surface of the groove portion connected to the terminal portion.
2. The coil component according to claim 1, wherein: A width dimension of the first recessed portion in a cross section parallel to the first side surface and in a direction perpendicular to the axial direction is greater than a width dimension of the groove portion in a cross section parallel to the first side surface and in a direction perpendicular to the axial direction.
3. The coil component according to claim 2, wherein: The flange portion has a second side surface and a third side surface adjacent to the first side surface, The first recessed portion is provided continuously with the second side surface and the third side surface.
4. The coil component according to claim 2, wherein: A depth dimension of the first recessed portion in the axial direction is greater than a depth dimension of the groove portion in the axial direction.
5. The coil component according to claim 2, wherein: The first recess has a shape having a tapered surface when viewed from the first side surface.
6. The coil component according to claim 1, wherein: The width dimension of the groove portion in a direction parallel to the first side surface at an opening portion of the outer surface of the groove portion is substantially constant from one end to the other end in a longitudinal direction perpendicular to the first side surface.
7. The coil component according to claim 1, wherein: The cross-sectional shape of the surface of the first recess which is farthest from the first side surface and is parallel to the first side surface and forms a boundary with the groove portion is equal to the cross-sectional shape of the surface of the groove portion which is parallel to the first side surface and forms a boundary with the first recess; the cross-sectional shapes of the surfaces parallel to the first side surface are such that the closer the distance between the first side surface and the surfaces is, the larger the cross-sectional shape becomes, and the surfaces formed by connecting the surfaces have a conical cross-sectional shape.
8. The coil component according to claim 7, wherein: The groove portion includes two inclined surfaces adjacent to the bottom surface and the bottom surface, The first recess has a shape in which a surface formed by connecting the surfaces parallel to the first side surface is a tapered plane continuous with the bottom surface of the groove portion and the two inclined surfaces.
9. The coil component according to claim 1, wherein: The groove portion includes two inclined surfaces adjacent to the bottom surface and the bottom surface, The bottom surface of the groove portion of the first recessed portion is recessed in a step shape.
10. The coil component according to claim 1, wherein: The flange portion has an inner surface on the winding axis side, and the first side surface has a second recessed portion at a portion adjacent to the inner surface and the first side surface and at a portion where the lead-out portion is led out.
11. The coil component according to claim 1, wherein: The flange portion has a fourth side surface opposite to the first side surface and a third recessed portion provided on the fourth side surface. A cross-sectional area of a surface parallel to the fourth side surface of a space portion formed on the fourth side surface as the third recess is larger than a cross-sectional area of a surface parallel to the fourth side surface of the groove portion connected to the terminal portion.
12. The coil component according to any one of claims 1 to 11, characterized in that: The outer surface of the flange portion has a long side and a short side, The first side surface of the flange portion is substantially parallel to the long side.
13. An electronic device, characterized in that: include: The coil component according to any one of claims 1 to 12; and A circuit board on which the coil component is mounted.